MRI (Magnetic Resonance Imaging) is an imaging method which magnetically excites nuclear spin of an object (e.g., a patient) placed in a static magnetic field with an RF pulse having the Larmor frequency and reconstructs an image based on MR signals generated due to the excitation. The above-described MRI means magnetic resonance imaging, the RF pulse means a radio frequency pulse, and the MR (Magnetic Resonance) signal means a nuclear magnetic resonance signal.